Why do I feel this way

I live in a really isolated place / small town and there isn’t much to do here unless you have friends which I don’t… Since giving birth 9 weeks I rarely leave my house unless it’s just for errands or my babies grandparents which is a highlight in my life right now! But I’d feel bad going there all the time specially because they have things to do and they live an hour out so it would be a little hard anyway. My husband is amazing but works nights so he’s gone or sleeping all day and I just feel alone Anyone else I know or used to hangout with lives 2 hours away and I’m not comfortable driving super far by myself with my baby the most I’ve driven alone so far is down the street to the store or library. I either take care of my son or am on my phone all day while he naps / sleeps Idk I just have been so sad lately and feeling so overwhelmed and alone and I don’t want it impacting my son or mental health :((